Electric motor



June 8, 1937. J. SCHICK 2,083,405

ELECTRIC MOTOR Filed Feb. '7, 1955 INVENTOR WJW. ATTORN EY.

Patented has, 1937 UNITED STATES PATENT OFFICE Claims.

This invention relates to an improved motor which is particularlyadapted for small spaces and which supplies a relatively large amount ofpower for its size. The motor is particularly Q adapted for dry shaversand similar tools held in the hand and is of a size to be housed in acasing that can be conveniently held in the hand.

The invention relates to a machine of this kind in which the motor is ofvery small size and very light in weight, and which is particularlyadapted for starting and stopping without the necessity of a switch,that is, employing a starting wheel for the armature shaft; This form ofmotor is contained in a casing of partioular form in which the startingwheel is exposed enough for intentional operation but is placed so thatit is protected against accidental interference by the hand when thecasing is go grasped.

The invention is also designed to provide a machine in which the motorcan be speeded up or slowed down to a, satisfactory and proper speed,even under varied frequency in the ourrent to compensate for variousloads on the circuit. The adjustment is readily adjustable from theoutside of the casing and provides for varying the distance between thecontact points and cam and simultaneously varying the distance betweenthe cam and the pivot of the contact arms.

The invention also relates to certain details of construction which willbe hereinafter more fully described and finally embodied in the claims.

The invention is illustrated in the accompany- 5- ing drawing in whichFigure 1 is a vertical section of the improved machine, the motor beingshown in elevation. Figure 2 is a face view of Figure l with the coverremoved. Figure 3 is a perspective view of the outside of the machine.Figure 4 is a detail section on line 4 in Figure 1. Figure 5 is adiagram of an alternative form of wiring. o

The casing is of a size to be conveniently held in the hand andcomprises a'tray part in and a cover H, held together by screws H2. Thepreferred form of casing or handle is of generally oval shape withflattened side walls and having a recess I3 in the bottom for thereception of a plug M by which current is supplied to the motor from thewire 55.

The motor is assembled before insertion in the casing and is secured byscrews 5 to lugs I! which lugs are integral with the casing. The lugsare molded, as is the casing, of material of the bakelite type andinserts of metal in the molds are embedded in the casing when it is madeand receive the screws without damage to the more fragile material ofthe casing.

The motor is of the magnetic type and com- 0 prises a field magnet l8 oflaminated iron and an unwound armature Hi. The field magnet is U-shapedwith its free ends forming poles 20. The poles form supports for twobearing plates 22 which bridge the space between the poles and support ashaft 23 on which the armature is fixed.

The cross arm of the magnetic field member is provided with the usualcoil 24 which is in series'with the contacts of the make-and-breakdevice which device is operated from the shaft 23. The make-and-breakdevice consists of two contact arms 25 and 26 which are placed onopposite sides of the shaft 23 and are provided with contact points 21.The arms 25 and 26 are made of material that is insulation for theelectric current. The arms 25 and 2B are fulcrumed on a stud 28 and heldagainst the shaft 23 by the spring 29, the ends of which are placed inthe notches 30 of the arms. The stud 28 has a head 3| and shoulder 32between which the arms are placed and held in alignment to cause fulland complete engagement when the contact points 21 meet.

The stud 28 is mounted in a manner to provide for adjusting the distancebetween the shaft 23 and the fulcrum of the arms 25 and 26. One mannerof doing this is by mounting the stud 28 on a lever 34 which is pivotedat one end, as at 35, to a strip 36 fastened to the field member byscrews 31. The free end of the lever projects through the casing and Ishow a slit 38 through which the free end of the lever passes and whereit can be moved by the finger. The spring 39 is one means for holdingthe lever 34 in its adjusted positions, the spring 39 being held inplace by the screw 40. The screw 40 and the upper screw 31 may beextended to engage the casing as additional securing means for themotor, if desired.

The contact points 21 are each provided with a screw-threaded stem Mwhich extends through a contact arm and beyond. The strips 42 areprovided with screw threaded holes which receive the screws 4| and thusheld in place. The strips are soldered or otherwise secured to the wires43 and 44, which wires are preferably stiif and provide their ownsupport. 7 The wire43 extends from one post it: and the other wire 44extends from one end of the coil 44. The other post 46 is connected by awire 41, to the other end of the coil 24.

The posts 45 and 46 are secured in place by A posts 45 and 46 arefastened. They are placed.

so that the outer ends are protected by being within the recess 13. Theplug l4 fits into the rocess and has terminals that embrace t e posts.

and thus place the machine in circuit when the plug is inserted.

The shaft 23 is made non-circular at the space between the contact arms25 and 26. The usual manner of forming the shaft at this place toproduce the proper cam action on the arms is to flatten the oppositesides as shown at 5| in Figure 2;

The shaft 23 has two other functions, one, transmitting motioh to theparts being driven and, second, acting as a starting and stopping mediumfor the motor.

The shaft 23 has a crank 52 which is formed by a circular portioneccentrically arranged at the end of the shaft. The crank operatesinside a forked end 53 of the lever 54. Around the crank 52 is a ring 55which ring also contacts with the inside faces of the fork. The ringrolls in the opposite direction from the direction .of the crank, thusminimizing the friction between these parts as the crank reciprocatesthe lever. The lever is pivoted intermediate its endsto the casing andextends beyond to have the end 56 engage the operated mechanism; in theform shown this being the inside cutter 51 of the shaving head of a dryshaver. The lever is pivoted on the headed shank 58 of the screw 59. Thebushing 6| is placed on the shank 58 and the sleeve 62 of the lever 54envelopes the bushing. This form of pivot provides adequate bearingsurface and ease of operation and can be quickly and economicallyassembled.

The starting wheel 63 is mounted on the end of the shaft 23concentrically to the shaft proper usually by providing a screw-threadedstem 64 which is screwed into the shaft. The casing has its outer faceprovided with a recess 65 and a bulged part 66 separated by a slot 61.The upper edge 68 of the bulged part is preferably curved. The startingwheel has its rim projecting through the slot and it is preferablytapered and roughened. This construction allows ready access to thewheel for starting purposes by twisting it with the thumb or finger. Thebulged part of the casing shields the wheel 63 from accidentalengagement at the sides or from the face of the casing when the casingis held in the hand under normal use.

This machine thus embodies, within a. small space, so small that themotor and its casing can be comfortably held in the hand, a powerfulmotor that weighs approximately a quarter of a pound. The motor can bestarted conveniently but the starting wheel while easy of access forstarting and stopping is guarded against accidental engagement by thehand when the casing is grasped.

The motor is adapted for use on both direct and alternating current. Inuse, especiallypn alternating current, a slight adjustment may benecessary if the load on the line is not constant or if there is achange in. the frequency. The motor is adjusted by moving the lever 34which movement Varies the distance between the fulcrum, that is, thestud 28, and the power, that be used for reducing the noise caused inradios and the like when usdon the same line. This wiring prevents thesurge of current back to the line when the contacts 21 separate and thusovercomes the cause of much of the objectionable noise in radios. Inthis form I employ a split coil 69 and l0 separated by an insulatingbarrier ll. One coil is interposed between one contact 21 and the lineon wire 44-41 and the other coil is interposed on line 43. Thisarrangement is found effective as it reduces the noise in radios to agreat extent.

Various changes can be made in the shape and proportion of the partswithout departing from the scope of the invention.

I claim:-

1. A motor comprising a field member having opposed poles, an armaturerotatable between the poles, ,a shaft on which the armature is secured,anon-circular portion on the shaft, a pair of contact arms bearing onthe non-circular portion, contacts on the free ends of the arms, afulcrum on which the arms are pivoted at the other end, resilient meansfor holding the arms against the shaft and a pivoted lever on which thefulcrum is mounted whereby the distance between the fulcrum and theshaft'can be varied.

2. A motor comprising a field member having opposed poles, an armaturerotatable between the poles, a shaft on which the armature is seofcontact arms bearing on the non-circular portion, contacts on the freeends of the arms, a fulcrunfon which the arms are pivoted at the otherend, resilient means for holding the arms against the shaft, a pivotedlever on which the fulcrum is mounted whereby the distance between thefulcrum and the shaft can be varied and means for holding the lever inits adjusted positions.

3. In a motor, an armature shaft having a non-circular portion, a pairof contact arms held resiliently against the said portion, a fulcrum forone end of the arms and means for moving the fulcrum toward or from theshaft whereby the throw of the free end of the arms may be varied.

4. A motor comprising a U-shaped field magnet, bearing plates bridgingthe open end of the field member, an armature shaft rotating in thebearing plates and extending beyond them, a starting wheel on oneprojecting end, a noncir cular portion on the other projecting end, a

lever pivoted on the field member, a. stud on the lever, a pair ofcontact arms bearing on the stud and on the non-circular portion, thefree end of the lever projecting for manual operation whereby thedistance between the stud and the shaft may be varied.

5. A motor comprising a U-shaped field magnet, bearing plates bridgingthe open end of the field member, an armature shaft rotating in thebearing plates and extending beyond them, a starting wheel on oneprojecting end, a non-circular portion on the other projecting end, alever pivoted on the field member, a stud on the lever, 21. pair ofcontact arms bearing on the stud and on the non-circular portion, thefree end of the lever projecting for manual operation whereby thedistance between the stud and the shaft may be varied, a crank on theshaft in rear of the starting wheel, a ring around the crank, a leverwith a forked end embracing the ring and a pivot for the leverintermediate its ends.

JACOB SCI-KICK.

